A Venezuelan oil minister once referred to his country's main export as the "devil's excrement." We’ll see how the death of Hugo Chavez affects production levels of this Faustian fuel—which influences both the global oil market and the climate.

Venezuela’s oil has problematic qualities. The thick, tar-like oil requires extra heat to flow. Once finally on the move, it's fed to refineries where the heavy oil must be what the engineers call "cracked." That chemical process removes excess carbon and readies the oil to be turned into the petroleum products we all use, from gasoline to plastics. The extra carbon, known as pet coke, is often burned and is more highly polluting than even coal.

These issues affect more than Venezuela. The Keystone XL pipeline is a bid in part to bring oil from Canada's tar sands to some refineries on the Gulf Coast that can handle it precisely because they were built to handle Venezuela's tarry mix. If more Venezuelan oil begins to flow the Keystone pipeline might prove extraneous.

But whether Canadian tar sands or Venezuelan heavy crude, more thick oil means more CO2 in the atmosphere. And that means a climate ever more hellish.